Nepheline Syenite
Nepheline syenite has three main areas of application;
- Ceramics
- Functional fillers
- Glass production
It is a naturally occurring, silica-free, anhydrous sodium-potassium alumina silicate, that delivers improved product performance and is accordant with modern environmental and industrial hygiene standards.
Nepheline syenite is a composed of three primary minerals: the albite form (sodium) of feldspar, the microcline form (potassium) of feldspar and nepheline (feldspathoid).
The existence of nepheline and the absence of crystalline silica is what sets this uniquely occurring rock apart from feldspar fillers, which contain just albite and microcline.
Like feldspar, it provides alkalis that act as a flux in the manufacture of glass and ceramics. In glass production, alumina acts as a matrix of stabilizer, enhancing the workability of molten glass, and increasing the resistance for scratching, breaking and chemical protection.
Specification
Typical Properties
| APNS 4 | APNS 5 | APNS 7 | APNS 10 | APNS 12 | |
| 75µm | 100% | 100% | 100% | 100% | 100% |
| 45µm | 99.9% | 100% | 100% | 100% | 100% |
| 30µm | 98.5% | 99.5% | 99.5% | 99.8% | 100% |
| 20µm | 90.0% | 93.0% | 99.0% | 99.5% | 100% |
| 15µm | 82.0% | 85.0% | 95.0% | 98.0% | 100% |
| 10µm | 63.0% | 65.0% | 85.0% | 97.0% | 99.9% |
| 5µm | 35.0% | 30.0% | 50.0% | 80.0% | 90.0% |
| 2µm | 13.0% | 48.0% | |||
| D50 (µm) | 7.0 | 8.0 | 4.5 | 2.5 | 2.1 |
| Bulk Density | 0.83 | 0.78 | 0.63 | 0.56 | 0.50 |
| Bulk Density | 0.83 | 0.78 | 0.63 | 0.56 | 0.50 |
| Oil Absorption (g/100g) | ~22 | ~22 | ~25 | ~31 | ~35 |
| Whiteness | 81 | 82 | 83 | 85 | 86 |
| CIELAB Color L: | 93.30 | 93.30 | 94.10 | 94.40 | 94.60 |
| CIELAB Color a: | -0.01 | -0.01 | -0.01 | -0.02 | -0.02 |
| CIELAB Color b: | 2.59 | 2.59 | 2.26 | 2.26 | 2.2 |
| Hardness (mohs) | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 |
| pH | 8.9 | 8.9 | 9.1 | 9.2 | 9.3 |
| Moisture | 0.10% | 0.10% | 0.15% | 0.15% | 0.15% |
Chemical Properties
| APNS | APNS 13 Ceramic Grade | APNS NF 13 Ceramic Grade | |
| SiO2 | ~ 61.50% | ~ 61.00% | ~ 58.00% |
| Al2O3 | ~ 20.80% | ~ 21.00% | ~ 23.20% |
| Fe2O3 | < 15% | ~ 0.13% | ~ 0.13% |
| TiO2 | ~ 0.03% | ~ 0.03% | ~ 0.05% |
| Na2O | ~ 8.40% | ~ 8.80% | ~ 9.70% |
| K2O | ~ 6.10% | ~ 6.00% | ~ 5.70% |
| CaO | ~ 0.75% | ~ 0.30% | ~ 1.00% |
| MgO | ~ 0.10% | ~ 0.05% | ~ 0.05% |
| L.O.I. | ~ 2.10% | ~ 2.20% |
Particle Size Distribution
| +75µm (200 Mesh) | Trace |
| +45µm (325 Mesh) | < 2.00% |
| -45µm (325 Mesh) | > 98.00% |
| D50 (µm) | < 10.0 |
| Moisture | < 0.3% |
